Single handle faucets, commonly referred to as mixer valves, that control both hot and cold water flow have seen vast consumer acceptance. These faucets are commonly constructed such that a handle or knob is movable in two distinct directions to adjust the mix of hot and cold water and to adjust the volume or flow rate.
The two basic types of mixer valves that have seen widest commercial acceptance are plate valves and ball valves. While ball valves offer a reliable one piece construction that is durable and easily assembled, plate valves offer a drive mechanism that allows motion of the handle in two desirable directions that appears to be universally accepted by the consumer. This desirable handle motion allows for an orbiting motion of the handle about a fixed longitudinal axis of the valve body and a rocking, i.e. pivoting, motion about a movable horizontal axis relative to the valve body. The horizontal axis is fixed with respect to the handle and is perpendicular to the longitudinal axis of the valve body. The one distinguishing characteristic of this type of handle motion is that when the handle is pivoted to an off position, the desired mix ratio of hot and cold water can be remembered by the location of the handle so that when the faucet is turned back on, the same mix of hot and cold water flows through the faucet.
Recently, ball valves have been devised that allow the handle to be operated in the same fashion as the commercially accepted plate type mixer valve. These ball type mixer valves require the introduction of another moving part in the form of a rotatable plate mounted above the ball valve element. Furthermore, these ball valves have been combined with plate devices which can be adjustably positioned about a cover opening through which the handle controls the ball valve to limit the total flow rate. Alternately or in addition, these limiting devices limit the maximum ratio of hot water to cold water and consequentially the maximum temperature of the mixed water at the outlet.
Various disadvantages arise when a ball valve is constructed such that its stem moves similarly to most plate type mixer valves. In particular, the ball valve element is mounted between elastomeric inlet seals positioned about the inlet ports of the vale body and a sealing gasket that is mounted under the valve cover or cap. The elastomeric inlet seals and gasket are all yielding and render a floating characteristic to the ball valve element between the valve body and cap. There is no positive lock or locator mechanism that securely positions the ball valve in place. Because the ball valve can be moved in a translational manner against the elastomeric elements, the operator when operating the handle can also move the handle a small amount in any direction including directions not contemplated in the design of the mixing valve. This unwanted motion renders a undesirable spongy feel to the operation of the faucet and an uncertainty to the operator as to the proper operation of the faucet. Furthermore, the spongy feel of the handle gives the impression that the handle is unstable and not assembled properly.
In order to reduce these disadvantages, a regulation ring has been incorporated in many ball valve mixing valves. The regulation ring is adjustably screwed onto the valve cap. The regulation ring pushes the sealing gasket downward against the ball valve element which in turn is pressed against the inlet seals. The downward placement of the sealing gasket and ball valve element reduces the undesirable motion but does not eliminate it. Furthermore, the combining of the regulation ring with known guide mechanisms which limit the handle's directional movement and with plate devices which limit the flow rate and temperature is unduly complicated and expensive.
What is needed is a ball valve type mixer valve that duplicates the handle motion of known plate valves that provide for swinging of the handle about the longitudinal axis of the valve body while retaining the advantage of having only one movable piece to operate the valve, in other words, without the introduction of a separate moving part. What is also needed is a ball valve assembly of the described type that eliminates the need for a regulation ring and provides for a valve that eliminates the possibility of the handle moving in a fashion that is different from that needed for its proper operation.